If you are running a website, then odds are you are doing some form of analysis on the usage patterns of your end users. There are many ways to do this but one of the most common is to use a client ...
The example sets the collect size to 1000000000 bytes (1Gb!) if no content length header value is found in the response. And if the content length header value is over 4mb, no restriction is done. Either case could trigger a TMM crash.